// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

package org.apache.doris.common.util;

import org.apache.doris.analysis.Expr;
import org.apache.doris.analysis.SlotRef;

import org.apache.commons.collections.CollectionUtils;

import java.util.Map;

public class ExprUtil {

    public static void recursiveRewrite(Expr expr, Map<String, Expr> derivativeColumns) {
        if (CollectionUtils.isEmpty(expr.getChildren())) {
            return;
        }
        for (int i = 0; i < expr.getChildren().size(); i++) {
            Expr e = expr.getChild(i);
            if (e instanceof SlotRef) {
                String columnName = ((SlotRef) e).getColumnName();
                if (derivativeColumns.containsKey(columnName)) {
                    expr.setChild(i, derivativeColumns.get(columnName));
                }
            } else {
                recursiveRewrite(e, derivativeColumns);
            }
        }
    }
}
